The Sealing Strips assist the brush roller on your Vacuum by sweeping alongside it allowing dust and debris from escaping, hence allowing a uniformed cleaning performance of your vacuum. From time to time you may need to change the sealing strip on your Household Vacuum cleaner; you may notice particles left on your carpet or hardfloor surfaces left behind after vacuuming. After making all the necessary checks as to why this is happening; such as a worn brush roller or strip, and your suction power. You may need to change your Sealing Strip.